Extracellular Vesicles Support the Survival of Serum-dependent cells in vitro

Abstract

Extracellular vesicles (EVs) are 30-150 nm in diameter and are released by cells into the extracellular environment. They facilitate intercellular communication and may be involved in cell survival. Although serum-dependent cells are not obviously affected by depletion of EVs from the serum, we previously reported that cells in serum that contain EVs were more resistant to the drugs, enoxacin and bis-enoxacin, compared to cells in serum without EVs. This change in resistance led us to examine whether EVs are sufficient to maintain serum dependent cells in vitro. Here, we tested the effect of EVs on the survival RAW 264.7 cells and on 4T1 murine breast cancer cells. EVs were isolated by differential centrifugation. EVs were counted over various time periods. Cells were grown in alpha or Dulbecco’s minimal essential media supplemented with FBS, EVs from various sources, or with no supplements. Cell growth was determined by cell counts. In media without supplementation, the RAW 264.7 cells and 4T1 cells died by three days. Media supplemented with EVs from FBS allowed the cells to survive in the absence of FBS for one week or more. Being able to perform experiments on cells supported by EVs will simplify the interpretation of experiments. Efforts are underway to determine their mechanism by which EVs support cell survival.

The dark side of foetal bovine serum in extracellular vesicle studies

“…However, it was found that 4T1 and RAW264.7 cells could grow in serum‐free media supplemented with FBS‐EVs. In fact, while these two cell lines were not able to proliferate in serum‐free media, their viability and cell proliferation increased when FBS‐derived EVs were added to serum‐free media (Christy et al., 2020). Moreover, Lehrich et al.…”

“…Murine breast cancer cells (4T1) and murine macrophages (RAW264.7) are two cell lines that require the presence of FBS in order to be maintained in culture (Christy et al., 2020). However, it was found that 4T1 and RAW264.7 cells could grow in serum‐free media supplemented with FBS‐EVs.…”